Prefer get_user_config_dir over get_home_dir for finding the panel config dir
For example:
`whiskermenu_path = os.path.join(GLib.get_home_dir(), '.config/xfce4/panel/', whiskermenu_file)`
`whiskermenu_path = os.path.join(GLib.get_user_config_dir(), 'xfce4/panel/', whiskermenu_file)`
issue